Currently folding rearview mirrors mounted outside the motor vehicles often use electric drive means for arranging the rearview mirror from an operating position to a folded position, and vice versa. Thus, the housing receiving the rearview mirror assembly can be driven in rotation to arrange it from the operating position to the folded position and vice versa through electric means or through manual means, as required by circumstances or needs.
In practice, one of the main problems encountered in this type of rearview mirrors is wind noise produced when the vehicle is moving. Noise, which adversely affects motor vehicle driving comfort, is due to the clearance between moving parts of the mirror assembly. Specifically, noise is due to the clearance between said rotating rearview mirror housing and the base element that is mounted fixed on the vehicle body and around which the rearview mirror housing is rotated when it is actuated.
The most common way to remove noise produced by the wind acting on said clearance is to provide a flexible seal between the moving parts of said type of rearview mirrors. In principle, providing a seal in the clearance between the rearview mirror housing and the base element solves the problem of wind noise when the vehicle is moving. However, this seal is often subjected constantly to friction produced as the rearview mirror housing is rotated relative to the base element when the rearview mirror is operated by the user from the operating position to the folded position and vice versa.
This friction during several cycles of rotation of the housing results in severe wear of the seal, which may become deteriorated, negatively affecting effectiveness. When the seal is worn as a given number of rotational operating cycles of the rearview mirror housing have been undergone, said seal can no longer perform its function efficiently to the extent that wind noise reappears again when the vehicle is moving. Furthermore, such friction causes high consumption of the motor resulting in that the motor itself loses mechanical properties, and even the total effectiveness earlier than foreseen.
To avoid this problem, the problem of wind noise that occurs when the vehicle is moving is currently addressed by supplementing said joint with a mechanism capable of displacing, i.e. moving away from and/or closer to, the rearview mirror housing relative to the base element when the former is driven to be rotated relative to the latter. This mechanism allows the two moving parts (housing and base) snugly fitted together when the mirror is in the operating position, allowing both elements to be moved away when the mirror is rotated for folding it. This mechanism usually consists of a series of wedges or ramps having an inclination designed for properly moving away or moving closer both elements together as they are rotated to each other.
Document WO2010151120 discloses a rearview mirror of this type. In this case, the rearview mirror includes a ramp arrangement, as stated above. In this particular case, the ramps are formed internally in the mirror mechanism, integral with a gearwheel for driving the mirror housing and the base element. Resilient members are provided adapted for pressing the mirror housing and the base element together. The main disadvantage of this solution is the large inclination that is required for the ramps in order to define the operating and folding end positions. This means that the motor has to work very hard to overcome the inclination which adversely affects motor consumption and service life.
Document EP2159102 relates to a rearview mirror that also uses an inclination system formed in the base element and the mirror housing to move the mirror housing relative to the base element when driven in rotation. The mirror provided in this document further includes a resilient member for pushing the mirror housing to the base element. This configuration is complex and requires high energy consumption as the force exerted by the high spring rate, single compression spring, which is provided to hold the assembly in a determined position, should be exceeded. Again, this results in that the motor has to work very hard to overcome the resistance by the resilient element, which adversely affects motor consumption and service life.
Although both solutions allow displacement between the mirror housing and the base element in order to minimize the effect of friction on the seal, or even to dispense with it, there however remains a need for a folding rearview mirror that is effective, simple, low consumption and cost effective. This is effectively achieved by a folding rearview mirror for motor vehicles such as the one to be described below. With the present rearview mirror additional technical advantages are also obtained, as will be seen hereinbelow.